Impinging-jet fuel-spray bar



1951 I c. s. MOORE ET AL 2,562,936

IMPINGING-JET FUEL-SPRAY BAR Filed March 1, 1946 Fig. v

Inventors Char/es S. Moore Dav/'0 Nov/Ir A Home Patented Aug. 7, 1951IMPIN GING-J ET FUEL SPRAY BAR I Charles S. Moore, Cleveland, and DavidNovik, Shaker Heights, Ohio Application March 1, 1946, Serial No.651,413

(Granted under the act of March 3,1883, as amended April 30, 1928;. 3700. G. 757) 4 Claims.

This invention relates to internal combustion engines and in particularto improvements in fuel-air mixing devices foruse in such engines.

In multi-cylinder engines, especially of the reciprocating aircrafttype, optimum performance has not always been achieved, due in manycases, to inadequate systems for delivering a homogeneous fuel-airmixture to all of the cylinders. It is recognized that coolingrequirements, knocklimited horsepower, fire hazards resulting frombackfires, and certain other operational characteristics are related to,or a function of, the fuelair mixture delivered to a cylinder. If thefuelair mixture varies between various cylinders, one, or in some casesseveral, of the cylinders may place definite performance limitations onthe remaining cylinders and hence reduce overall performance below theoptimum obtainable when all cylinders receive the most desirablefuel-air mixture. -In general, overall best economy andmaximumreliabllityare"obtainable only provided all cylinders functionunder substantially identical conditions, which again is possible, onlyprovided they receive a fuel-air mixture of optimum characteristics.

One of the objects of the invention is to provide the induction systemof a combustion engine with a device which will introduce the fuel in amanner such' that a large area of fuel is exposed to the air flowwhereby improved atomization and/ or vaporization occurs.

Another object is to provide a device which deliversgreater quantitiesof fuel in some portions of the induction air than is delivered to otherportionsto compensate for non-uniform fuel distribution which resultsfrom bends or turns in an induction system. A further object is toassociate a fuel delivery device with respect to a plurality of airthrottle valves in such manner that fuel is delivered into an air streamat the point of highest velocity under variable throttle settings.

Various other objects and advantages of the invention will becomeapparent from the following description, accompanying drawings, and

appended claims. r g

,I t draw s Fig. his a side elevation, partly insection, of oneembodiment of the invention;

Fig. 2 is an enlarged perspective of a portion of Fig. 1; and

Fig. 3 is a modified form of the invention illustrated in Fig. 1.

Referring to the drawings, l represents a portion of a. carburetor, orthrottle body, for a combustion enginein" which is pivotally mounted apair of butterfly valves 2, 3. Dotted lines illustrate the closedposition of these valves and full lines" a artiany open position. Valves2 and 3 are linked or geared together to operate in unison and inopposite directions of rotation. One form of connection to operate thevalves in this manner is shown by segmental gears l6, IT in Fig. 3.

The numeral 4 illustrates a tube having sets of jets or orificesdisposed along its length, these being in pairs having their axes in thesame plane and arranged so that the axes of each pair intersect. One setof these jets is shown at 5, 6 and another set on the opposite side ofthe tube at l, 8. The efiiux of fuel from jet 5 impinges upon the effluxof its companion jet 6 to form a thin fiat fan shaped spray, whichpresents a, relatively large area of fuel surface to the air flow foratomization and vaporization and hence improves the homogeneity of thefuel-air mixture.

In large engines of the class described it is common practice to employcarburetors or throttle bodies having two or more air tubes, oftenreferred to as choke tubes or barrels. Fig. 1 illustrates aninstallation whichwould be expedient in a two or four barrel carburetor.Tube 4 is located between, downstream, and parallel to the butterflyvalve shafts 9, l0. While Fig. 1 shows only two valves, it will beunderstood that the installation would be substantially the same withtwo or more pairs of barrels, the additional pairs being arranged sothat each throttle shaft would be extended to pass through theadditional barrels.

In a multiple barrel installation as above referred to, the tube 4 couldbe constructed, in one of its forms, as a generally cylindrical tubehaving longitudinal grooves or indentations II and [2, the sides ofwhich contain the impinging orifi'ces. Fuel would be supplied to thetube by means of a connection l3 connected to a suitable metering systemin the carburetor in any convenient manner well understood in the art.

In many installations it is necessary to connect the carburetor orthrottle body to the engine by means of adaptors or conduits whichinclude curved passages through which the fuelair mixture fiows. Anadapter of this sort is shown at M, the end remove from its connectionwith the carburetor being suitably secured to a supercharger casing orother portion of the engine which provides a region of distribution tothe individual cylinders. Where a conduit of this type is employed it isnot uncommon for a homogeneous mixture entering such conduit to bedelivered therefrom as a non-homogeneous mixture due to separation orconcentration of fuel particles resulting from centrifugal orgravitational forces. As illustrated, such concentration would beexpected in the zone shown at l5, this zone being more rich in fuel thanthe remainder of the passage through l4. Thisefiect can be corrected bythe present invention by proportioning the fuel jets on opposite-sidesof the spray tube in such manner that unequal 3 amountsof fuel aredelivered thereby. In the embodiment illustrated, the jets 5, B whichdeliver fuel in the general direction of the outside of the curvedadaptor l4 would be proportioned to deliver less fuel than jets I, 8which deliver fuel in the general direction of the inside of theadaptor. Thus the adaptor [4 would receive fuel I 3 the mixture wouldrender it uniform when it is delivered from the adaptor. The amount offuel proportioned to the opposite sides of tube 4 would depend on theparticular configuration of the adaptor between the carburetor andcommon distribution region for the individual cylinders. The location ofspray tube 4 relative to the butterfly valves forms an important part ofthe invention. These valves form, in effect, a variable throat venturi,the throat of which, or region of highest air velocity, is at the mostrestricted zone between the valves. Generally this zone will be, at, or.near a point which is at a minimum distance between the downstream edgeof the valves. This can be better understood from a consideration ofFig. 1. In any position other than full throttle where the valves wouldboth be vertical, a portion of the air would flow between the loweredges of the valves and the throttle body. This being a point ofrestriction would necessarily be a point of high air velocity. The airwould then flow around the outside or non-adjacent valve edges and sincethe flow area is continually increasing downstream the air velocitywould be reduced so that adjacent the downstream edge of the valves nearthe throttle body walls, there would be a region of relative lowvelocity. On the other hand, the portion of the air flowing between thevalves would continue to increase in velocity due to the increaseddownstream restriction, the point of highest velocity of the air flowacross the cross section of the throttle body being in a region betweenand substantially equidistant from the downstream tip of throttlevalves. Atoinization and/or vaporization of fuel is considerablyenhanced by locating the spray tube in the high velocity regionpreviously described.

Fig. 3 illustrates another embodiment of a throttle body, primednumerals representing parts corresponding to those of Fig. 1. In thisembodiment, the throttle valves 2', 9 are pivoted along one edge ratherthan at their centers. The body I could be partitioned into a number ofcylindrical barrels as in the embodiment previously described, or couldbe in the form of a single air tube, one form of which could begenerally rectangular in transverse cross section. The pivot pointneednot be located completely to one edge as shown but could be between thecenter of the valve and one edge, that is, having unequal portionsprojecting from the pivot point. Like the embodiment previouslydescribed, this modification would effect a region of highest airvelocity downstream and between the adjacent downstream edges of thevalves at which point the spray tube '4' would be located.

The principal use of the arrangements previously described are forimproved or controlled fuel distribution. The device, however, hasutility for liquids other than the main fuel supply to an engine, and itis within the spirit of the invention that they be included accordingly.One example is its use for injecting water or injectedfor the samepurpose.

4 water alcohol mixtures or other similar liquids used for theprevention of detonation when the engine is operating at or near itsmaximum power. Alternately, fuel and water could be Another use would befor priming the engine for starting.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What we claim is:

1. In a device for mixing fuel and air in the induction system of aninternal combustion engine the combination of an unsymmetrically shapedconduit in which the fuel-air mixture ratio is greater along one sidethan along the other due to centrifugal or gravitational forces, a pairof valves for controlling the airflow through said conduit in such amanner as to form a zone of relatively high velocity in the air passingthrough said conduit, a tubular fuel conduit disposed at substantiallyright angles to said conduit in said relatively high velocity zone anddownstream from said valves, and a plurality of paired orifices in saidfuel conduit disposed in such manner thatthe fuel spray discharged intosaid zone from one half of each pair of orifices impinges on the fuelspray discharged by the other half of each pair of oriiices, said pairedorifices further arranged to discharge fuel substantially downstream andto each side of said zone in unequal amounts whereby a homogeneousmixture of fuel and air flows through said conduit during normaloperations.

2. The device as set forth in claim 1 wherein each valve has an axis ofrotation disposed intermediate opposite edges.

3. The device as set forth in claim 1 wherein each valve has an axis ofrotation adjacent one edge thereof.

4. In a fuel-air induction system having a mixing passage and a throttlemeans therein, a substantially tubular fuel conduit disposed in saidpassage at substantially right angles thereto and downstream from saidthrottle means, two righ angled grooves in the relatively downstreamsides of said fuel conduit, a wall of one groove being coplanar with awall of the other groove on opposite sides of said conduit, and theremaining two walls being parallel to each other and to the axis of saidpassage, and a plurality of paired orifices in the walls of said groovesdisposed in such manner that the fuel spray discharged into said passagefrom one of each pair of orifices impinges on the fuel discharged by theother of the corresponding pair of orifices.

' CHARLES S. MOORE.

DAVID NOVIK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Mock l Mar. 27, 1945

